Total ordering is an ordering that defines the exact order of every element in the series. Partial ordering of elements in a series is an ordering that doesn’t specify the exact order of every item, but only defines the order between certain key items that depend on each other. The meaning of these words is … Read more
What are the essentials of distributed real-time systems? A distributed real-time system composes two challenging sets of properties which are imposed by the problem domain or the solution domain (or both.) Distributed A distributed system links a number of independent computing entities with local properties by way of a communication mechanism. As a consequence, algorithms … Read more
The evils of too much coupling between services are far worse than the problems caused by code duplication The author is very unspecific when he uses the generic word “coupling”. I would agree with certain types of coupling being a strict no-no (like sharing databases or using internal interfaces). However the use of common libraries … Read more
If you’re using the single machine scheduler then do this: from dask.diagnostics import ProgressBar ProgressBar().register() http://dask.pydata.org/en/latest/diagnostics-local.html If you’re using the distributed scheduler then do this: from dask.distributed import progress result = df.id.count.persist() progress(result) Or just use the dashboard http://dask.pydata.org/en/latest/diagnostics-distributed.html
If you want to use Go’s channel concepts in a distributed program, perhaps check out the Go Circuit framework. It provides a framework for running multi-process programs (possibly spread over multiple machines), allowing you to use channels to communicate between those processes.
Yes, Apache Spark will unpersist the RDD when the RDD object is garbage collected. In RDD.persist you can see: sc.cleaner.foreach(_.registerRDDForCleanup(this)) This puts a WeakReference to the RDD in a ReferenceQueue leading to ContextCleaner.doCleanupRDD when the RDD is garbage collected. And there: sc.unpersistRDD(rddId, blocking) For more context see ContextCleaner in general and the commit that added … Read more
check also GlusterFS Edit (Aug-2012): Ceph is finally getting ready. Recently the authors formed Inktank, an independent company to sell commercial support for it. According to some presentaions, the mountable POSIX-compliant filesystem is the uppermost layer and not really tested yet, but the lower layers are being used in production for some time now. The … Read more
Since Spark uses Hadoop File System API to write data to files, this is sort of inevitable. If you do rdd.saveAsTextFile(“foo”) It will be saved as “foo/part-XXXXX” with one part-* file every partition in the RDD you are trying to save. The reason each partition in the RDD is written a separate file is for … Read more